One important aim for people is to work, have fun and amusement by using electrical devices such as computers, mobile phones etc. conveniently and comfortably in anywhere, that is omnipresent human computer interaction. However, the existing solution does not achieve good results, on the one hand, though the prior mobile phone has strong calculating and processing ability, the size of the phone is small, resulting in the display screen is too small to be suitable for watching, and the keyboard is too small to be operated conveniently by users, on the other hand, though the prior notebook may be portably carried, by comparing with the mobile phone, it still seems cumbersome and can't be carried conveniently, resulting from the size is much large and the weight is much heavy. If the notebook is designed smaller, the same situation as the phone that the notebook is not used conveniently will happen.
In addition, most of the prior electrical devices have an external operating and controlling panel, a display panel, and a keyboard or a mouse etc., which will actually have big influence on the reliability and stability of the devices, such as electrical devices on the vessels (which need strong resistance on salt, fog and humidity etc.,). Meanwhile, the size of the devices will become big because of the external operating and controlling panel, and the display panel.
For the prior portable or wearable human computer interaction system using projection, one typical manner is to constitute a human computer interaction system with a depth sensor, which is formed by using a projection-invisible optical projection unit with infrared structured light and an infrared image sensing unit, and a visible light projector etc. (some systems even include a visible light image sensing unit), however, the depth sensing unit (such as kinect of Microsoft) utilized by such system normally has big power consumption and volume, especially for an application of the smart phone, its size gets bigger because it needs adding infrared projection and infrared image sensing unit additionally in the phone. The other manner is to constitute a portable human computer interaction system which is formed by one visible light projecting unit and one visible light image sensing unit, however, such system needs producing invisible structured light for obtaining the operation of touching the projecting plane by fingers accurately, and the principle of method for producing the invisible structured light is generally to require projecting frequency of the projecting unit bigger than 75 Hz, normally 120 Hz, as well as frame rate for image collecting of the image sensing unit is same as frame rate for projecting, therefore the power consumption of such system would be excessive too because the frame rate for projecting and image collecting is very high. In addition, the computation complexity of such system will be enhanced resulting from that the invisible structured light still has coding and decoding.
In summary, the prior electrical devices have the following defects, (1) size of the operating and controlling panel or the display panel is too small to be suitable for watching and operating, (2) the volume and weight of the electrical devices with the operating and controlling panel or the display panel is too big to be portably carried, (3) reliability and stability of the electrical devices with the operating and controlling panel or the display panel is too weak to work under some special severe environments, and (4) both power consumption and size of the prior portable or wearable human computer interaction system with projection is too high and big.